Currently, there are many works devoted to what causes the asteroid danger for earthlings, what it consists of, as it is revealed. Some scientists propose solutions that would minimize the risks posed by outer spaces and the bodies in it. For a simple layman, asteroids are often nothing more than falling stars that you want to make wishes for, but sometimes a celestial body causes a massive catastrophe. What is it about?
Typical situation
If we turn to sources explaining whether an asteroid hazard is a myth or reality, we can find out that small bodies falling on the surface of our planet are usually either warm or hot, but they do not repent. Such meteorites fly through the Earth’s atmosphere in a few seconds, and there’s not enough time to warm up properly. There are also known cases when the body, flying through the air layers, was covered with an ice crust. This is due to the fact that the core of the asteroid is very cold.
When a meteorite falls, most often you can see either a black object or a black with a reddish tint. If the meteorite is composed of iron, it is characterized by increased hardness. Such items were previously used to make tools. This was the only source of iron available to man in antiquity.
One of the causes of asteroid hazard is meteor shower. This term refers to a situation where several square kilometers appear to be under the bombardment of celestial bodies. Over the past three centuries, such rains have been recorded at least 60 times. In fact, this rain is a fall from the sky of numerous stones and pieces of iron that disperse over a large area. Celestial bodies fall on houses, can fall directly on a person. However, from practice it is known that this happens extremely rarely.
There are big
When analyzing the asteroid hazard, it is necessary to clarify the risks associated with the fall of large celestial bodies. Such collisions leave traces that remain for a long time, cracks on the planetary surface - craters. Astronomers have found that impact craters are on the surface of all the celestial bodies of our system, which have a dense upper layer with a fairly high level of hardness. Mars is especially expressive in this regard.
Among all the celestial bodies that fell on the surface of our planet, it is especially known that it is ten kilometers in diameter - it fell approximately 36 million years ago. It is believed that it was this natural disaster that caused the extinction of life that existed then on the planet. The dominant animal species at that time were dinosaurs that could not survive due to climate change.
What is known from history?
For a long time, people have known that stones can fall from the sky. Since ancient times, various scientists and thinkers have been thinking about the problem of asteroid-comet hazard. In the sources that have reached our days, one can see a fixation of events that happened a very, very long time ago. Among the oldest, it is worth noting information reflecting the events of about 654 years before the beginning of the current era. Manuscripts of Chinese sages tell about bodies falling from the sky at the time.
You can learn about meteor showers from sacred biblical texts, the works of Plutarch, Libya. Found even more ancient sources dating back to about the XV century before the beginning of the current era. Such ancient evidence has been preserved by the Chinese. And in 1492, for the first time, the French chroniclers reliably recorded the fall of a large celestial body. The event happened near the village of Ensisheim.
In the Slavic chronicles you can see blocks, also dedicated to observing the fall of celestial bodies. For the first time, these appeared in sources dated 1091. The following mention belongs to 1290. There were later references.
On average, until the 18th century, the scientific community denied the relevance of the asteroid hazard, believing that large bodies simply could not fall from the sky. All stories about such events were recognized as nothing more than fiction, and the prominent minds of that time were skeptical of any news on this topic. The situation changed in 1803 when meteorite rain fell on a site not wider than 4 km in length, amounting to 11 km in French lands.
During this event, numerous fragments fell on the ground - more than three thousand elements were counted in total. This fact is considered the first that scientists have officially recognized. From this moment there is a new research area - meteorics. At first, Bio, Hladni, Arago were engaged in it.
New Age - New Approaches
The nineteenth century is marked by the development of a new science. Her progress was accompanied by the emergence of yet another discipline. The new direction was called the theory of catastrophes due to the fall on the planetary surface of celestial bodies. However, at that moment, scientists did not have a clue about the asteroid-comet hazard, and therefore did not support the initiators. For about a century and a half, this discipline devoted to disasters fought steadily for life, with a limited number of followers, and was not recognized by the scientific community at the world level.
The situation changed in the middle of the last century. Today, only in our country there are several largest institutions dealing with the risks associated with space bodies, as well as possible measures to prevent damage. Such universities, institutes are in the metropolitan area, in Novosibirsk and St. Petersburg.
Should we talk about the asteroid-cosmic danger if most of the bodies, as you can see from old sources, fell on the planet almost unnoticed by the public? Some time ago, they organized an official collection of information about space objects that fell on our planet. Particularly curious are the data on the fall of bodies in the area of ​​Tsarev village in early December 1922. The total area on which meteor shower was estimated at 15 km 2 .
In 1979, about 80 fragments were found here, weighing 1.6 tons in total. The largest meteorite made of stone weighed 284 kg. Until recently, it was the largest meteorite in the entire territory of our country. Some time later, a more terrible catastrophe occurred near Chelyabinsk. The largest fragment of a meteorite that fell near the city weighed 570 kg.
Save everything
Despite the lack of understanding of the asteroid hazard as a global problem, for a long time people have already begun to collect meteorites, which were subsequently investigated. Unique samples have been collected since 1749. However, it is known that even 1.2 thousand years before the beginning of the current era, celestial shrines, i.e. meteorites, were preserved in the temple of Arcadia. Today, only GEOCHI has approximately 180 copies found in our country, and another 500 received from foreign sources. There are more than 16,000 samples in total. Among them are representatives of almost any type. In total there are samples from 45 powers. The collection weighs more than three dozen tons.
The largest meteorite found on our planet was discovered in 1920. It was found in Namibian lands near the settlement of Grootfontein. The celestial body was given the name Western Goba. This is an iron mass weighing 60 tons. Its dimensions in meters are almost three by three. The asteroid above is flat, smooth, therefore, somewhat resembles a table. He only slightly protrudes above the earth's surface. Below this object is relatively uneven. It is deepened into the earth's surface by about a meter.
Several more objects are known whose weight exceeds ten tons. There is information about this in Mauritania. It is believed that he is somewhere in Addar. Sources indicate a meteorite made of iron, whose weight is one hundred thousand tons, and the dimensions are estimated at about 100 * 45 m.
The dangers
Three major events of the last century testify to the asteroid hazard problem. On the last June day of 1908, at about seven in the morning, local time, the Tunguska meteorite fell. After 22 years, on August 13, 1930, a heavenly scourge fell on the Amazon. Astronomers from England saw three huge celestial bodies that fell somewhere near this river. As established a little later, the event happened near the Brazilian-Peruvian border. The force of the fall was compared with the power of a hydrogen bomb; she tripled the previous meteorite. This natural disaster caused the death of several thousand people. As eyewitnesses later told, around eight in the morning the shade of the star suddenly changed to bloody, everything was covered with darkness.
The next terrible event happened in 1947, February 12th. The fall occurred on the Sikhote-Alin site, it happened about 11 hours. The zone was struck by meteor shower. The inhabitants of Khabarovsk were able to see how a huge meteorite fell on the planet. It was later established that he weighed several thousand kilograms. Friction caused the object to split even during the flight. One celestial body fell apart into many thousands, hail of iron falling on the taiga land.
The study of the rocks showed more than a hundred funnels spread over a site exceeding a couple of square kilometers in size. The diameter of the funnels ranged from 2-26 m. The largest in depth was estimated at six meters. Over the next half century, about 9 thousand small fragments and about three hundred large fragments were discovered. The largest weighed almost two tons, the smallest - only 0.18 g. The total weight of the collected was estimated at three dozen tons.
1990s
In short, the asteroid danger is well illustrated by the events recorded in the 90s of the last century. So, on May 17, 1990, a little more than half an hour before midnight, a celestial body of iron suddenly fell. This happened in the Bashkir lands, on the field where the workers of the Sterlitamansky state farm grew bread. The largest part of this cosmic body was estimated at 315 kg. The fall was accompanied by a bright flash for a few seconds. Residents of the area noted that they heard a roar and crackle. The sound reminded the thunder accompanying a thunderstorm. The fall caused the appearance of a ten-meter deep crater half its diameter.
The following year, a meteorite fell in Sasovo on April 12. In the annals, this event is written as happened at 1 h 34 min. The fall caused the appearance of a 28-meter radius in the radius of the funnel. The moment of impact was the cause of the instant loss of 1800 tons of soil. All the poles located near this place, set up to provide telegraph communication, were damaged - they leaned toward the center of the crater.
In 1992, a meteorite hit the state of New York. The event is dated October 9, at eight in the evening. The object was given the name "Peekskil". At this point, many knew (at least briefly) about the asteroid hazard, possible risks, as well as meteorites in principle. It so happened that the fall of this very heavenly body gathered a lot of eyewitnesses. Not reaching the earth's surface for about 40 km, the celestial body fell apart.
We counted 70 blocks. One of them crashed into a car near a residential building, breaking through the object. Later, when he was weighed, it turned out that he weighed 12.3 kg. It was comparable in size to a soccer ball. The chip was valued at $ 70,000.
Continuing the chronology
The next case, which indicated the asteroid danger of small bodies of the solar system, dated October 7, 1996. An asteroid fell in the village of Lyudinovo near Kaluga, whose weight was then estimated at several tons. Flying, he seemed to the locals a huge ball of fire. The glow emanating from the body was comparable in brightness to that characteristic of the moon in the maximum phase. Locals noted a strong hum, which the asteroid attracted the attention of those who did not have time to sleep (the event happened at about eleven in the evening).
A year later, asteroids attracted the attention of French residents. A celestial body fell on a car on the night of April 10, weighing which showed a half kilogram. The object was black, clearly burnt, in shape resembled a baseball ball. Analysis of the composition showed basalt. The flight itself attracted the attention of many; it was possible to record the event on a video camera.
In 1998, in Turkmenistan, in a field where cotton was grown, a meteorite fell near the village of Kunya-Ugrench, whose weight was estimated at 820 kg. This event, once again reminiscent of the asteroid danger of small bodies of the solar system, happened on June 20. The fall caused a crater of five meters depth. The width of the funnel is 3.5 m. A falling meteorite was a source of bright short-term glow, loud sounds. It is known that the roar produced by him was heard by people located a hundred kilometers from the point of impact.
End of a decade
In 1999, an asteroid-comet hazard swept the metropolitan region - a celestial body fell in the direction of Shcherbakovka in Moscow. In the same year, a fall was recorded in Chechen lands.
At nine in the morning on January 18, a meteorite fell in the northwestern Canadian lands. The heavenly body was given the name Tagish Lake. According to local scientists, when the body only entered the atmosphere of our planet, it numbered from 55 to 200 tons, and in diameter was at least four meters, but possibly reached 15 m.
At the time of entry into the atmosphere, the asteroid exploded, the explosive force amounted to three trotyl kilotons. People who had the opportunity to observe the event with their own eyes then talked about a bright flash, a strong clap that shook the ground, glass began to rattle, and the roofs shook off the snow cover. The information received from the sensors confirmed the explosion in the air. About a month later, fragments were discovered.
The place where the meteorite exploded was marked by a fragment weighing about 0.2 kg. The analysis showed carbonaceous chondrite saturated with carbon compounds, including organic ones. Among all the celestial bodies that fell on our planet and then were studied, only about 2% are formed by the same substance.
As can be concluded from the above information, more often a fall occurs at night than in the daytime.
Explosion in the air
Analyzing the asteroid-comet hazard, scientists found that not every celestial body reaches the surface of our planet. If the dimensions of the item are less than a meter, it completely burns out during the passage of the air layer. If the size exceeds a meter, such an object can reach planetary soil, partially burning. It is believed that there are such celestial bodies that completely burn out before reaching a surface of 20-75 km. There are many celestial bodies flying over a short distance from our planet.
In 1972 of the last century, an event occurred that potentially pointed to the colossal asteroid hazard of asteroids. A set of random factors led to the fact that over Utah, a celestial body with a diameter of 80 m fell into the atmosphere at a speed of about 15 km / s. It so happened that the trajectory turned out to be gentle, so the body flew about one and a half thousand kilometers, and somewhere above Canadian lands just flew out of the Earth’s atmosphere, setting off on a further journey through space.
If such an object exploded, then the force of the explosion would exceed the accompanying Tunguska meteorite - and that was estimated at 10-100 megatons. If an asteroid exploded, at least two thousand square kilometers would be affected.
Risks: so close
Again, asteroids and asteroid dangers were discussed in 1989. A kilometer-wide asteroid flew between our planet and its satellite. Scientists discovered it when it was already six hours after overcoming the site as close to the planet as possible. If the Earth would pull this body, it would surely collapse on the ground, and the consequences would be disastrous. Presumably, this would be accompanied by the appearance of a winch with a diameter of at least a dozen kilometers, or even a half dozen.
In 1991, at a distance of about 17,000 km from our planet, an asteroid flashed, the dimensions of which are estimated at ten meters. Astronomers noticed this body when it was already moving away from the planet. The following year, a nine-meter asteroid moved between us and the Earth’s satellite, and in the 94th, a celestial body erupted in the Earth’s atmosphere, weighing five hundred tons. This happened at a distance of about 20 km from the earth's surface. The heavenly body burned down.
Another flew at a speed of 24 km / s, weighed from one to two tons. 100 000 , , . 9 . 19994 . 14 .
To fully understand the asteroid danger, you need to know what the fall of celestial bodies leads to. An extremely terrible consequence is, of course, human sacrifices. In 1996, Lewis published works in which he summed up his paleontological research. He calculated that only during the existence of civilization, accompanied by the fixation of history in writing, the victims were counted in the thousands.
A total of 123 events were investigated that were the cause of injuries, injuries, and deaths. Of course, the buildings were also harmed - and that was only in a couple of centuries. If you turn to the biblical tests, you can see the story of the destruction of Sodoma and Gomorrah. In the Qur'an, the 105th sura tells about the death of people due to asteroids. The blocks of Mahadharata, the works of Solon from Ancient Greece are devoted to the same. The book “Chilam Balam”, which tells about the victims of meteorites, has reached us. It is composed by the sages of the Mayan people.
In 1950, Fedinsky took up the topic; six years later, Schultz's work saw the light of day. They both studied the asteroid danger and damage, the consequences associated with it. They found that over the past half millennium there is official information about 27 cases of the entry of celestial bodies into buildings. At least 15 times asteroids fell on the road. Two cases are described when objects hit cars.
In 1021, a meteorite fell on African lands, which caused the death of many people. In the 1650th, the monk died from getting a fragment of no more than eight grams in weight. It happened in Italy, in a monastery. In 1749, people were injured on a ship. Cases of wounds due to celestial bodies were recorded in 1827, 1881, 1954. In our country, such cases date back to 1914 and 1925.
Climate and more
An asteroid hazard is associated with possible climate change. To many ordinary people, the fall of a large celestial body seems to be the source of a terrible cataclysm that happens when an object collapses on the ground. However, tsunamis, explosions are not the only danger. There is a risk of a "nuclear winter", saturation of the atmosphere with nitrogen oxides. In the future, this provokes acid precipitation, a decrease in the concentration of compounds designed to protect the soil, the planet’s water from aggressive solar radiation. This can cause a phenomenon in science called the "ultraviolet spring."
The asteroid hazard is manifested by the consequences associated with electric fields. When a celestial body enters the earthly layers, it can receive a certain charge. Suppose it was a comet no more than ten meters in diameter. Its power becomes comparable to a nuclear bomb. The speed developed by the celestial body reaches 70 km / s.
Is it possible to minimize risks
The current level of technological development is such that there are no effective ways to protect against an asteroid hazard, especially when a dangerous body is several kilometers in diameter, since there are no ways to remove an object from the planet. The only thing that is possible is to take measures in order to minimize harm to the population. If you identify the body for a year or more, then there will be enough time to create shelters underground and above it, and to form bases and reserves. There will be enough time to make protective equipment.
Presumably, in the near future, people will have sufficiently effective and accurate technologies to predict the fall of celestial bodies. Studies have shown that the “nuclear winter” due to the fall of a ten-kilometer celestial body, which had already happened once, lasted within a month. However, other consequences, including a violation of the chemical atmospheric composition, may persist for a longer period.